Plate processing machine



Nov. 28, 1967 E. J. HORNER PLATE PROCESSING MACHINE Filed June 18, 1965 2 Sheets-Sheet I l 28, 1967 E J. HORNER 3,354,807-

PLATE PROCES S ING MACHINE Filed June 18, 1965 2 Sheets-Sheet 2 I7 F/6.4 U

ATTORNEY United States Patent 3,354,807 PLATE PROCESSING MACHINE Ellwood J. Homer, Armond, N.Y., assignor to R. Hoe & Co. Inc., New York, N.Y., a corporation of New York Filed June 18, 1965, Ser. No. 465,087 3 Claims. (Cl. 9594) ABSTRACT OF THE DISCLOSURE A plate finishing machine having a pair of pressure rollers partially immersed in a developer liquid and a guide rack for guiding the plate and negative together into the nip of the rollers and up between them so as to squeeze them together and effect a transfer of emulsion from the negative to the plate. The tank which holds the developer liquid is provided with a shaft journaled in its side walls, the shaft carries paddles which vigorously agitate the developer solution as the shaft is rotated.

This invention relates to printing plate processing equipment.

More particularly, the invention is concerned with equipment for preparing sheet metal offset plates for printing, by squeegeeing the same together in a developing solution with a photographic negative of the subject matter to be reproduced, thus transferring to the plate the unexposed areas of the photographic negative.

A variety of machines for this purpose have been available, such, for example, as that shown in the Ludwig Patent 2,792,768, and such machines have found extensive and satifactory use in the preparation of comparatively small and thin plates, such as used in office printing equipment. The machines heretofore made, have not been adapted to the preparation of comparatively large, thick plates for publication printing and the general object of the present invention is to provide an improved plate finishing machine which is adapted to such use.

In general, the type of machine to which the present invention is directed includes a pair of rollers which dip into a developing bath, together with means for guiding the plate and negative together through the nip of the rollers, so as to squeeze the same together in the bath and effect the transfer of emulsion from the negative to the plate.

It is an object of the invention to improve the drive and registering arrangements in such machines so as to obtain registration and control of feeding of the high quality required for publication work.

It is a further object of the invention to provide improved sheet guiding and liquid stirring means for such machines.

With the foregoing and other objects which will appear in the following full description in mind, a machine embodying the invention in a preferred form will now first be fully described with reference to the accompanying drawing, and the features forming the invention will then be pointed out in the appended claims.

In the drawing:

FIG. 1 is a plan view of a machine embodying the invention in a preferred form;

FIG. 2 is an end elevation of the machine of FIG. 1;

FIG. 3 is a section on the lines 5, but showing the developer tank partly in elevation; and

FIG. 4 is an enlarged section on the line 44 of FIG. 3.

The machine frame comprises end plates and 11, side rails 12 and a pair of pressure rollers 13, 14 which are rotatably journaled in the frame by means of their shafts 15, 16. Associated with the respective rollers 13, 14 is a pair of feed tables 17, 18 which support the plate and film for registering and feeding to the machine. Feed roller pairs 19, 21 and 20, 22 cooperate with these feed tables for propelling the plate and film thereon into the grip of the pressure rollers 13, 14 in a registered and timed relation. Rollers 19 and 20 are journaled in the end plates 10, 11 by their shafts 23, 24, while rollers 21 and 22 cooperating therewith are rotatably supported in arms 25, 26 secured respectively to the shaft 27, 28 which are rotatably adjustable in the end frames. Arms 29, 30, secured to the shafts 27, 28, are urged upward by poppet springs 3-1, 32 supported on the side rails 12, so as to force the rollers 21, 22 under predetermined spring pressure against the rollers 19, 20. Handles 33, 34 secured to the shafts 27, 28 provide for depressing the rollers 21 and 22 out of operating relation to the cooperating rollers 19, 20. A motor reducer unit 35 is mounted on the frame, and drives the shaft 23. Gears 23', 13', 14 and 24', which are carried on the shafts of correspondingly numbered rollers, together with idle gears 36 and 37, which are ro tatably carried on the back frame plate, serve to drive the operating rollers at a predetermined speed and in timed relation to each other.

The rollers 13, 14 dip into a pool of developing solution contained in a rectangular tank 40. Tank 40 is supported on four pivoted legs or struts 41, which, in turn, are secured in pairs to cross shafts 42 journaled in the side rails 12. Shafts 42 are rotatably coupled together by crank arms 43 and connecting rods 44, so that turning one of the shafts 42 by means of the handle 45 raises or lowers the tank 40 while maintaining its horizontal position unaltered. Tank 40 has a standpipe extension 46 protruding through an opening in the front frame plate of the machine, and thus providing for filling of the tank and inspection of the level of solution therein. Within the tank 40 is a framework comprising guide plates 47, these plates running around in parallelism to the pressure cylinder surfaces for guiding the plate and film thereto, and being held in position by longitudinal rods 48. Mounted on one of these rods (left side) is a member 54 comprising a block which rests on the bottom and against the side wall of the tank 40 thereby supporting the rod and the guide plates 47 held thereby. Centrally of the plates 47 is a shaft 49 carrying a number of paddle assemblies 50 (one such assembly between each pair of guide plates). The shaft is accommodated in downwardly opening notches 51 in the plates 47, and a pair of springs 52 support the ends of the shaft and urge it upwardly. The springs 52 are wrapped about rod 48 (right side) and its curved portions rest against the bottom and side wall of the tank 40 thereby urging the rod 48 (right side) and the guide plates carried thereby upwardly and toward the member 54. The shaft carries at its ends rollers 53 which engage the ends of pressure roller 14, the shaft being set sufficiently to one side so that the rotation of the roller 14 causes the shaft and paddles carried thereby to rotate and maintain a vigorous but accurately regulated agitation of the solution.

Preferably, one of the pressure rollers (in the machine illustrated, the roller 14) is hard surfaced (stainless steel) while the other is rubber covered. In use, the film and plate are placed upon feed boards, being registered thereon against the back (outer and upper) ends of the boards and along one edge thereof. In so registering the film or plate, the operator holds down the handle 33 or 34 while getting the sheet in proper position and then releases this handle so that it is gripped, in properly registered position, between rollers 19, 21 or rollers 20, 22, as the case may be. By reason of the gearing interacting on the rollers, it will be apparent that the sheets, and more particularly their back edges, are accurately positioned 3 with relation to each other and to the pressure rollers. Once the sheets are in position, the machine is ready to operate. Motor 35 is started and the plate and film are fed down by and between the roller pairs 19, 21 and 20, 22 over the guide plates and around under the rollers 13 and 14 and then upwardly between these rollers, where thetwo sheets are brought into contact and pressed firmly together. They continue to pass as a unit in a vertically upward direction and out of the line of engagement of rollers 13, 14. They are thereafter separated and the remaining preparation takes place in the usual Way.

What is claimed is: 1. A plate finishing machine comprising cooperating pressure rollers and means for supplying a plate and emulsion sheet thereto, a developer tank containing developing liquid partly immersing the said rollers, a guide rack tor to stir the developer when the machine is running.

2. A plate finishing [machine comprising cooperating pressure rollers and means for supplying a plate and emulsion sheet thereto, a developer tank containing developing liquid partly immersing the said rollers, a guide rack comprising a plurality of guide plates spaced from the roller surfaces and substantially parallel thereto for guiding the plate and sheet down under the rollers and then up between them, an agitator comprising a shaft journaled in the said rack and carrying a plurality of paddle elements spaced along the rollers, a drive wheel for said agitator fixed to the said shaft beyond the plate and sheet engaging portions of the rollers, and means pressing the said drive wheel against a said roller for driving the agitator to stir the developer when the machine is running, the last said means comprising spring elements supporting the said agitator shaft within the tank and urging it upward, whereby engagement of the said wheel determines the shaft position relative to the rollers.

3. A plate finishing machine according to claim 2, in which the said rack comprises a member seating on the bottom and against a wall of the tank, and the spring means acts against the rack on the opposite side therefrom, whereby the drive wheel is urged up against the pressure roller and said opposite side of said rack is urged upwardly and toward said member to move said member down against the bottom and side wall of the tank.

References Cited UNITED STATES PATENTS 2,792,768 5/1957 Ludwig 89 3,189,325 6/1965 De Belcler 9589 3,277,808 10/ 1966 Frohock 95-89 FOREIGN PATENTS 1,020,866 12/ 1957 Germany. 1,135,294 8/1962 Germany.

85,131 5/ 1957 Netherlands.

NORTON ANSHER, Primary Examiner.

FRED BRAUN, Assistant Examiner. 

2. A PLATE FINISHING MACHINE COMPRISING COOPERATING PRESSURE ROLLERS AND MEANS FOR SUPPLYING A PLATE AND EMULSION SHEET THERETO, A DEVELOPER TANK CONTAINING DEVELOPING LIQUID PARTLY IMMERSING THE SAID ROLLERS, A GUIDE RACK COMPRISING A PLURALITY OF GUIDE PLATES SPACED FROM THE ROLLER SURFACES AND SUBSTANTIALLY PARALLEL THERETO FOR GUIDING THE PLATE AND SHEET DOWN UNDER THE ROLLERS AND THEN UP BETWEEN THEM, AN AGITATOR COMPRISING A SHAFT JOURNALED IN THE SAID RACK AND CARRYING A PLURALITY OF PADDLE ELEMENTS SPACED ALONG THE ROLLERS, A DRIVE WHEEL FOR SAID AGITATOR FIXED TO THE SAID SHAFT BEYOND THE PLATE AND SHEET ENGAGING PORTIONS OF THE ROLLERS, AND MEANS PRESSING THE SAID DRIVE WHEEL AGAINST A SAID ROLLER FOR DRIVING THE AGITATOR TO STIR THE DEVELOPER WHEN THE MACHINE IS RUNNING, THE LAST SAID MEANS COMPRISING SPRING ELEMENT SUPPORTING THE SAID AGITATOR SHAFT WITHIN THE TANK AND URGING IT UPWARD, WHEREBY ENGAGEMENT OF THE SAID WHEEL DETERMINES THE SHAFT POSITION RELATIVE TO THE ROLLERS. 